Governing means



Sept. 4, 1945.

F. c. REGGIO GOVERNING MEANS Filed'May e. 1940 5 Sheets-Sheet 1 Sept. 4, 1945. F. c. REGGIO GOVERNING MEANS Filed May 6, 1940 5 Sheets-Sheet 2 2 frwerzior:

F. C. 'REGGIO GOVERNING MEANS Sept. 4, 1945.

Filed May 6, 1940 5 Sheets-Sheet 3.

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F. C. REGGIO GOVERNING MEANS Sept. 4, 1945.;

5 Sheets-Sheet 5 Filed May 6, 1940 Patented Sept. 4, 1945 STATES PATENT OFFICE;

2,384,340 GOVERNING MEANS Ferdinando Carlo Regglo, Harwich Port, Mass.

Application May 6, 1940, Serial No. 333,529

19 Claims. (Cl. 264-3) This invention relates to governing means for prime movers and to automatic regulating devices, and in so far as the subject matter is common it is a continuation in part of my copending patent applications Serial No. 236,249, filed October 21, 1938, now Patent No. 2,313,264, issued March 9, 1943, and Serial No. 254,355, filed February 3, 1939.

In one of the preferred embodiments of the invention the governor or regulating device in-- cludes hydraulic servomotor means controlled by a pilot valve. The latter is actuated by means responsive to an operative condition such as the speed of a prime mover, and is further subject to a fluid pressure load which varies with changes of adjustment of said servomotor means.

An object of the invention is to provide an improved construction and arrangement of governor for prime movers.

Another object is to provide a simple and compact construction and arrangement of hydraulic governor.

A further object is to provide a hydraulic governor for prime mover, having a pilot valve actuated in response to changes of speed and load of said prime mover.

A still further object resides in the provision of resilient means for continuously rotating the plunger pilot valve and transmitting an actuating load thereto. I

Another object resides in the provision of simple and accurate means for adjusting the speed difference of the prime mover between no load and full load operation of the latter.

A still further object of the invention resides in the provision of an automatic regulating mechanism haying simple and effective antihunting arrangement.

It is to be clearly understood that the governor according to the invention may be used in 'connection with any suitable prime mover or engine, to regulate the supply of energy or fuel thereto or to vary other operative condition upon which the speed thereof is dependent. The governor may thus be employed to actuate an admission valve, 2. throttle, the control member of a fuel injection pump, or it may be used for regulating the pitch of a variable-pitch aircraft propeller to control tlgce speed of the engine driving said propeller, e

One example of embodiment of the invention is disclosed herein, in which the governor is employed to control the fuel supply of an internal combustion engine provided with fuel injection units separately mounted on the cylinders thereof. In this specific embodiment a-further object involves the omission of the mechanical linkage between the governor and the fuel injection pumps and the substitution therefor of a hydraulic column whose pressure may b varied by said governor. The substitution of such hydraulic column in place of a mechanical linkage may be of'especial use where the fuel injection elements are far removed from the governor and from one another. Under such circumstances the friction losses incidental to the considerable length of mechanical linkage are avoided. Furthermore the danger that a damaged fuel pump element might interfere with the operation of the governor and the control of the other pump elements is eliminated.

The fuel delivery of the injection pumps is a predetermined function of the pressure in the liquid column interconnecting pump elements and governor. The latter includes a pressure regulating valve designed to control the pressure of said liquid column and thereby the engine fuel supply. The adjustment of said valve depends on th simultaneous values of the forces transmitted thereto by:

(a) Resilient means under the control of the operator for setting the desired engine speed;

(b) Means responsive to the engin speed; and

(c) A hydraulic pressure substantially equal or proportional to the pressure of said liquid column and therefore varying as a predetermined function of the engine fuel supply.

One more specific object of 'the invention is to provide means whereby the ratio between the hydraulic pressure mentioned in c and the pressure of said liquid column may b adjusted substantially between 1 and the lowest possible value consistent with steady engine operation. Varying this ratio between said values causes the "speed droop" of the engine, or the speed range between full load and no load, to vary between its maximum designed value and its minimum actually possible value.

The above and other objects and advantages of the invention will be apparent as the description proceeds; and while I hav illustrated and described some of the preferred embodiments of valve is actuated in response to changes of one or more operative conditions'other than speed, in order to avoid irregular operation thereof such as hunting or throbbing. In the following description and in the claims various details will be identified by specific names for convenience, but they are intended to be as generic in the application as the art will permit.

A few examples of embodiment of the invention are illustrated in the accompanying drawings in which: a

Fig. 1 is a longitudinal section-showing one arrangement of hydraulic governor and fuel injection pumps;

Fig. 2 is a fragmentary section along line 2-2 of Fig, 1:.

Figs. 3 and 4 are in part elevation and in part longitudinal sections of modified arrangements of hydraulic governor and injection pumps;

Fig. 5 is a. fragmentary longitudinal section showing an alternative construction of part of the hydraulic governor;

Figs. 6 to 9 are longitudinal sections through hydraulic governors of a different type;

Fig. 10 is a fragmentary section showing a partial modification of the governor'of-Fig. 1;.

Figs. 11 and-l2 are sections of other modified types of governors;

Fig. 13 is a fragmentary section of a modified arrangement of fuel injection pump.

A fuel injection pump [3 for internal combustion engine, shown in Fig. 1, has a plunger |4 having a reciprocating motion of constant stroke in a barrel I! provided with a port ll. At the inner end of the plunger, beyond an annular groove It, the surface of the plunger contacting the bore of barrel "and adapted to intermittently close the port I1 is limited by at least one inclined edge. The effective discharge stroke of the plunger is that portion of the inward displacement of the plunger d rin which the port I1 is cl and the liquid fuel displaced in pressure chamber I3 is forced through a spring loaded valve and a nozzle into the engine cylinder.

Such valve and nozzle, not shown in detail in the drawings, is not a part of the invention, and may be of any suitable type. Owing to the inclined edge at the inner end of plunger M the effective stroke and in turn the fuel delivery varies with the angular adjustment of the plunger relative to port ll. 1

An intermediate portion of plunger I4 is slidably but non-rotatably mounted in a pinion 24 axially located between the barrel ll and a washer 2! resting against a shoulder of pump housing l3. The outer end of plunger II is formed with a head 23 holding a seating collar 21 for the coil spring 23 and is enclosed by a cover 2l-slidably mounted in a bore of housing l3. A rocker arm 33 operated from an engine driven cam actuates the. plunger for the pressure stroke, the spring 23 effecting the return or suction stroke. A small screw 3| through the housing l3 engages a slot.

32 in. the cover 23 to keep the latter in place when the rocker arm 33 is removed.

The plunger |4 may be angularly turned for .adjustment of the fuel delivery by a rack cut in A calibrated coil spring 42 is mounted between the opposite end of rack 35 and a threaded adjustable cap 43 provided with a lock nut 44. A

rod 45 of small diameter secured to raclr 35 and coaxial therewith" extends through a central opening of cap 43 and can be manually operated to temporarily modify the axial adjustment of rack 35. The extreme position that the latter can reach toward the right may be adjusted by means of a screw 48 provided with a lock nut and cooperating with a notch 41 formed in the rack An annular chamber 50 is provided in housing l3 about the barrel l5. Chamber 80 communicates with pressure chamber I! through port H, and with inlet chamber 31 through a duct 6|. The injection pump I3 is attached to the engine by means of cap screws 52.

'In a multicylinder. engine all of the fuel pumps i3 are connected with the fuel feed line 40, the inner section of which is. sufficiently large to secure a substantially uniform fuel pressure in all points of the line. Two such pumps I3 connected with'line 40 are shown in Fig. 1.

- The adjustment of rack and in turn the fuel discharge are dependent on the value of the fuel pressure in line 40. An increase in fuel pressure causes a movement of rack 35 toward the right until the increased hydraulic load on the latter is balanced by a correspondingly increased resilient load of spring 42. The preferred arrangement is such that a displacement of rack 35 toward the right causes an increase of fuel delivery of the pump. Fuel pressure in feed line and fuel discharge of pumps 3 will therefore simultaneonsly increase or decrease according to a predetermined relationship.' The springs 42 of the various pumps 3 have the same rate of defiection and their loads are initially adjusted by means of the threaded caps 43 so that with a same amount of fuel.

Control of the engine fuel supply may thus be obtained by governing the fuel pressure in the feed line 40.

'To that end a fuel transfer pump 33 shown as a pump-of the gear type but that may be of any other suitable type, driven from the engineer by other prime mover, draws fuel at substantially atmospheric pressure or other substantially constant pressure from a supply line 3| and discharges it into lines 32 and 43. Between discharge and inlet ports of pump 33 there is a bypass 63 which is controlled by a,valve 34 loaded by a spring 65 held by an adjustable cap 33 set I j for a determined maximum-value of the fuel pressure in lines 42 and 43. When the pressure in the latter reaches said value, valve 34 opens the by-pass and prevents any further increase in fuel pressure. I

.A speed governor ll includes a shaft I l rotatable in a sleeve 12 and driven from the engine through a gear I3 and a pinion 14. Shaft carries fiyballs I! having extreme outer and inner positions determined by shoulders 13 and 11 formed on shaft 1|. Inwardl'y extending arms of 'fiyballs II engage'a shoulder of the pilot valve 30, which valve is mounted in a bore of body 3| coaxial with shaft II and is adapted to rotate and reciprocate therein. A splined rod s3, slidable in a splined axial hole broached in the shaft 1|, carries at its upper end the inner race of a thrust bearing 89 the outer race of which is secured to a sleeve 85 slidable in a bore of housing 19. A pinion 96 connected with speed control lever 91 engages a rack cut in sleeve 85 and serves to adjust the axial position of the latter.

A compression spring 99 has its upper coil tightly wound about a groove formed at the lower end of rod 83, while its lower coil is solidly seated in a groove machined at the upper end of the pilot valve 89. A groove 9| is machined in the intermediate portion of valve 99 and is permanently connected through a port 92 with the line 92, while it communicates with fuel supply line 6| through a port 93 whose open area is dependent on the axial adjustment of valve 89. Below valve 99 a compensating chamber 95 is connected with port 92 and line 92 through an orifice 96 adjustable by means of a needle valve 91, and is connected with port 99 and line 9| through an orifice 99 adjustable by means of a needle valve 99. When valve 99 is in its lower position communication between compensating chamber 95 and port 99 is interrupted.

When the engine is inoperative the fuel pressure in lines 92 and 99 is the same as in the supply line 91. The injection pumps I 3 are adjusted for no delivery. The pilot valve 89 is in its lower position and closes the orifice 98. The 'valve 69 is also closed, as well as port 93. Assuming the fuel transfer pump 69 to be driven from the engine, as the latter is cranked fuel is discharged into lines 62 and i9 and the pressure therein rises rapidly and reaches its maximum value whereupon valve 69 opens the by-pass '69 and prevents a further increase in pressure. Accordingly the injection pumps l3 are adjusted for maximum fuel delivery and, actuated by the rocker arms 99, inject fuel into the engine cylinders. As firing occurs in the latter and the engine speed increases and approaches the value corresponding to the setting of the speed adjusting lever 91, valve 89 is liftedby the fiyballs l and uncovers first the orifice 98 and afterwards a portion of the area of port 93. The area of orifices 96 and 99 adjusted by needle valves 91 and 99 respectively being very small, the amount of fuel by-passed through the compensating chamber 95 is very small and has no noticeable effect on the value of the fuel pressure in the feed line 99 whenever the speed of the transfer pump 69 is above that corresponding to low engine cranking speed.

Since the capacity of the transfer pump 69 is in excess of the total maximum discharge of the injection pumps l9, when the engine is operating under the control of the governor, that is when the by-pas's 69 is closed by valve 64, the excess fuel is by-passed through the open area of port 99. Aj'downward displacement of valve 99 causes a reduction of said open area and therefore an increase in speed of the fuel flowing through said area and a corresponding increase of pressure in the feed line 49. Conversely, an upward displacement of valve 89 causes an increase of the open area of port 93 a reduction of speed of the fuel by-passed through said port and a corresponding decrease of pressure in line 49.

Th adjustment of the pilot valve 89 relative to pc 93 is dependent on the simultaneous actions of the load of spring 99, of the centrifugal force acting on the flyballs l5, and of the fuel pressure in the compensating chamber 95. It is therefore dependent on the adJustment of the Neither stops are shown in the drawings.

speed adjusting lever 81, on the engine speed and on the engine fuel supply. v

Any governor in order to be stable must regulate the speed of its engine, at least temporarily, in such a manner that the speed is lower for full load than for no load. If the difference between maximum and minimum speed divided by the average speed, or speed droop, is high the speed regulation is soft" and the change from a given amount of engine fuel supply to another caused by a change of load on the engine is not abrupt but gradual. A smaller speed droop causes a more abrupt speed regulation because small speed variations involve large changes in the engine fuel supply. Assuming the orifice 98 to be closed by the needle valve 99 while the orifice 96 is open, the fuel pressure in the compensating chamber is substantially the same as in the feed line 49. The actual engine speed is depend ent on the load of the compression spring 99 minus the load applied to the lower end of valve 89 by the fuel pressure in chamber 95. When the engine is operating under steady load the valve 99 is in stable equilibrium; if the engine load increases the engine speed decreases and the centrifugal force acting on the flyballs 15 also decreases causing a downward movement of valve 89 and an increase of fuel pressure in feed line 49. The discharge of the injection pumps IS increases and the engine resumes speed. The fuel pressure in the compensating chamber 95 also increases while the load of spring 99, due to the extremely small vertical motion of valve 89 is substantially unchanged. The equilibrium of the 'governor will be reestablished when the engine reaches the speed that corresponds to that value of the centrifugal force of flyballs 15 that balances the load of spring 99 minus the load due to the fuel pressure in chamber 95. The engine speed under the heavier engine load will therefore be lower than the engine speed under lighter engine load.

Conversely when a drop in engine load occurs the engine accelerates and the ilyballs 15 lift the valve 89 causing a reduction of fuel pressure in line 49 and in compensating chamber 95. The fuel discharge of injection pumps l3 decreases causing the engine speed to decrease until the centrifugal force of fiyballs 15 balances the load of spring 99 minus the load due to the fuel pressure in chamber 95. The decrease in engine load will therefore cause an increase of engine speed. The condition of stability of the governor, that is the ability to cause the engine speed to decrease -when the engine load increases, is thus satisfied. The desired nominal engine speed is set by means of lever 81 that may be adjusted by the operator or by automatic devices. Anticlockwise rotation of lever 91 increases the load of spring 99 and in turn the engine speed. A stop may be provided to limit the anticlockwise rotation of lever 81 thereby determining the maximum engine speed, while an adjustable resilient stop may limit the clockwise rotation of the lever to set the engine idling speed.

Clockwise rotation of lever 8! beyond its position determined bythe resilient stop causes valve 89' to.

uncover port 93 completely thereby stopping the engine.

The stabilizing or anti-hunting effect obtained by the application of an axial variable'fluid pressure load to the pilot valve 99 may more clearly and distinctly be described as follows:. If the engine decelerates, as it happens when the load thereon is increased, the spring overcoming the diminishing centrifugal force applied to the flyballs moves th pilot valve to downward so as to increase the pressure in the fuel line Illand displace the hydraulic servomotor member or pressure-actuated control rack toward the right to increase the engine fuel supply. In the ward the left and a decrease of engine fuel supply. The engine decelerates, the speed thereof drops to a value lower than normal, and hunting .may continue indefinitely. c To correct this condition of instability various compensating or anti-hunting devices have been proposed. The anti-hunting arrangement according to the inventionas illustrated in Fig. 1 consists essentially in the provision of a fluid pressure chamber 9| atone end of the pilot valve II for, exerting on the latter an axial variable pressure load in the following manner. .As upon increase of load the engine decelerates, the

spring so overcomes the diminishing centrifugal load and shifts the pilot valve 80 downward, causing a pressure increase in the fuel line and a. displacement of the rack 35 toward the right so as to increase the engine fuel supply.

As a result the pressure in chamber 95 also increases and restrains the downward movement of the pilot valve. Although this restraining pressure exerted on the pilot valve isvery small as compared to the centrifugal force, it causes the valve II to resume its normal adjustment quickly so that overtravelof the valve, overco'rrection by'the servomotor member 35 and overspeed of the engine do not occur.

.Whenthe engine accelerates upon a drop of engine load. the action of the governor is the .absence of any change of pressure in chamber 85 the displacement of the pressure actuated memreverse of thatjust described, causing a pressure 1 drop in chamber 95 and thus restraining the upward displacement of the pilot valve In so as to avoid overtravel of the latter and overcorrection' on the part of the servomotor member 35. The danger of hunting is thus eliminated.

In th foregoing the assumption has been made that orifice II is closed and the fuel'pressure inthe compensating chamber OI acting on valve ll 'hassubstantially the same value as the fuel pressure in the feed line I and in chambers 31 wherein said pressure actuates the racks II, the

operation 'of the governor being thus similar to that disclosed in my said copending application Serial No. 236,249, in which the governor has a predeterminednon-adiustable amount of speed droop. 'Itis to be clearly understood that according to the invention, where it is not desired that said speed droop be adjustable, the governor of Fig. -1 may. be simplified by' eliminating the orifice II and the needle valve 8!. Needle valve I'I may also be eliminated, or used for controlling the dampening eifect of orifice 86 on the movements of valve 80. Similar modifications may obviously'be introducted in the other forms of governors illustrated in the drawings. If we now assume that orifice I is closedby needle valve 0'! while the orifice 8| is open, the pressure in chamber OI will be constantand'the adjust ment of valve 80 will be dependent on the load of spring 9. and on the centrifugal force of fiyballs. II, and substantially independent of theengine fuel supply. No restraining action is exerted on the pilot valve upon initiation of the correcting movement-0f the servomotor member 36. Operation of the governor is therefore likely to be unstable.

Obviously when both orifices l8 and ll are Open the fuel pressure in chamber 8 has a value comprised between the pressures in lines ll, and 6!. Assuming, for simpliclty's sake, that the pressure in line II is equal to the surrounding atmospheric pressure, the effective pressure 9- in the compensating chamber is where m is the efi'ective pressure in line ll and a1 and as are the open areas of orifices II and II respectively. That is, the ratio between the fuel pressures in chamber 95 and in line ll maybe varied between 1 and 0 by properly adjusting the needle valves 01 and as. The speed droop varies substantially proportionally with said ratio.

Any determined value of speed droop within the designed limits of the governor corresponds to a definite ratio between the open areas of orifices t8 and 8!. Yet the open area of either one or the other of said orifices may be arbitrarily chosen so as to obtain a suitable dampening effect, or "dash pot" action, on valve ll.

The only friction that-the governor has to overcome is that opposing the axial displacement its barrel and remain stationary at the end of its discharge stroke with the load of spring II insufilcient to bring it back against the rocker arm- III, the pump would stop delivering fuelto its cylinder, but it would not interfere with the control of the remaining pumps, while with a coil:-

ventional mechanical linkage interconnecting al the racks ii the damaged pump might prevent the regulation of the other pumps thereby putting the engine out of control.

A further advantage of the present infection system is the possibility of checking the operation of each pump while the engine is operating by temporarily increasing or decreasing its. fuel delivery by means of rod 48.

said surges the hydraulic load applied to the racks II has a pulsating character. The of said high frequency pulsation of the load applied to the racks may be reduced, if it should appear desirable, by partially modifying the iniection pump ll of Fig. 1 as shown in Fig. 13, in which fuel from the feed line "I is led through conduit "8 to the annular chamber surrounding the pump barrel and its port. Said chamber.

where th surges of the fuel pressure originate,

is connected with chamber 462 into which the rack 460 extends by means of a duct 466 provided with a plug 404 having a small orifice adapted to dampen the high speed surges while it does not appreciably interfere with the comparatively slow motion of the rack due to the action of the governor. The spring 42 will be preferably designed so that its load is considerably in excess of the friction resistance opposing the sliding motion of the rack 35, r other load which may be exerted thereon, so that variations in the value of the latter load or friction will be comparatively negligible, and the adjustment of the pressure actuated rack 35 will be substantially determined by the fluid pressure in chamber 31, I

Obviously, non-adjustable orifices may be substituted for the needle valves shown in Fig. 1. A partial modification of the latter is indicated in Fig. 5, in which a compensating chamber I formed in the governor body I06 at the lower end of valve 80 communicates through an orifice I01 adjustable by means of a needle valve I08 with a duct I09 connected through an orifice IIO adjustable by means of a needle valve I II with a conduit H2 leading to the fuel supply line indicated by numeral 6| in Fig. 1, and connected suppressed and pressure variations therein may be delayed by the cushion chamber H6. The rate of pressure change in the chamber I05 is dependent upon the effective area of the orifices 8 i3 and H0 as well as on the volume of the air chamber H6. Where the volume of the latter is large and the orifices H3 and H0 are small the pressure variations in chamber I05 occurring upon a certain alteration in the adjustment of the servomotor member 35 or 202 are slower' than they would be with a smaller air chamber H6 and/or larger orifices. The effective volume of the air chamber and the orifice areas may thus be dimensioned or adjusted so as to obtain the desired magnitude and lag in the restraining pressure exerted on the pilot valve so as to adapt the governor or regulator to suit systems which respond with various degrees of promptness to the controlling movement of the servomotor. It will be obvious that in substitution for or in addition to the air chamber H6 other equivalent cushioning means may be provided such as resiliently movable wall means, spring loaded plung er, or bellows or diaphragm means; and that non-adjustable orifices may be substituted for needle valves Ill and I00. I

In injection systems in which the fuel injection pumps are mounted on the engine cylinders it may be convenient to provide for their continuous cooling and venting by means of an active circulation of fuel therein. Such an arrangement, including various elements already disclosed in detail, is shown in Fig. 3, in which a transfer pump I2I draws fuel at substantially constant pressure from a fuel supply line I20 and discharges it under pressure into the feed line I22. The injection pumps I24 are connected in parallel between the feed line- I22 and the return line I30 from which fuel is led to the I38 of governor I42 is substantially the same: Between the discharge port of the transfer pump I2I and the fuel feed line I22 a fuel strainer or filter, not shown in the drawings, may be inserted.

In the governor body I42 .a bypass I50 co nnects the inletport I38 with port I46 partly covered by the valve I44 and communicating with the fuel supply line I20. The by-pass I50 is controlled by a spring-loaded maximum pressure regulating valve I52 having the same function as valve 64 of Fig. 1. Operation of the governor is similar to that disclosed in connection with Fig. .1 and it is therefore regarded unnecessary to again describe it in detail.

In the foregoing injection systems the hydraulic medium used in the governor and in the hydraulic operating connection between governor and injection pumps is the liquid fuel burnt in the engine cylinders, such as Diesel oil, or gasoil, or gasoline.

However according to the present invention other hydraulic mediums may be used, for example the engine lubricating oil as it is illustrated in the arrangement shown in Fig. 4 of the drawings, in which the engine injection pumps I60 are supplied with fuel by way of a fuel line I62 connected through a conduit I64 with the annular chamber I66 surrounding the pump barrel and its port [68,. The fuel pressure in line I62 is maintained at a suitable value by a conventional transfer pump.or by gravity. When the engine operates, fuel is intermittently admitted to the pressure chamber I12 and forced by plunger I10 through an injection valve, not shown in section, into the engine cylinder.

A pump I14 driven from the engine or other suitable prime mover draws, lubricating oil at substantially constant pressure from line Iifi connected with the engine oil sump or other suitable reservoir and discharges it under pressure through line I18 and port IBIlinto an upper groove I62 formed in the pilot valve I84 0f the engine-driven governor I86. A lower groove I88 formed in th same valve is connected through port I90 with the oil supply line H6. The portion I92 of valve I84 comprised between grooves I02 and I controls a port I94 communicating by way of lines I96 and I38 with the chambers 200 of each of the fuel injection pumps I60, into which chambers one end of racks 202 extends. A by-pass 204 controlled by a spring-loaded valve 206 connects the discharge and inlet ports of pump I14. The diameter of port I94 and the axial length of portion I92 of valve I84 are equal so that when the latter is in its neutral position as shown in Fig. 4 port I94 is closed, and a small axial displacement of valve I84 above or below its neutral position causes port I94 to communicate with groove I88 or groove I82 respectively. The governor operates as follows: a substantially constant pressure is maintained in line I10 and in groove I02. This pressure is higher than the pilot valve I84 slidably and rotatably mounted in its bore is actuated in the same way as valve 88 of Fig. 1, that is valve I84 is controlled by the simultaneous actions of a spring adjusted by way of lever 288 of flyballs driven from the engine and f the oil pressure in the compensating chamber. (The effects of changes of the adjustment of valve I84 are also the. same as for the valve 88 of Fig. 1, that is an upward movement of the valve, connecting line I88 with the low pressure groove I88 and. line I18, causes a decrease of pressure in chambers 288 and a corresponding reduction in the engine fuel supply, while a downward movement of valve I84. connecting line I88 with the high pressure groove I84, causes an increase of pressure in chambers 288 and a corresponding increase of engine fuel supply. The restraining action exerted .on the -pilot valve I84 is also the same as that already disclosed in detail in connection with the Pilot valve, 88. The operation of the governors of Fig.

of valve 242 by way of a duct 288. The inlet port 288 of transfer pump 228 is connected by way of duct 288 with the fuel supply line 284, with port 284 controlledby the valve 242, with the low d and Fig. 1 is therefore similar. Under steady\ engine load operation a small amount of lubricating oil flows through port I84 to compensate for the oil by-passed through the compensating chamber.

In-injection pumps I88 designed for handling fuels of poor lubricating property a duct 2I4 may be provided to lead lubricating oil from the chamber 288 to a groove formed'in the bore of the pump barrel in order to lubricate the plunger I18. Thus the pressure of the lubricant increases with the load of theinjection pump.

The governor illustrated inFig. 4, for example, includes a fluid pressure actuated plunger 282 controlled by means of the valve I84 and having a rack and pinion connection with the injection pump plunger I18. to control the engine fuel pply. It is to be clearly understood, however, that according to the invention any suitable fluid pressure actuated means may be substituted for the plunger 282. Said fluid pressure 'actuated means may be, or include, a piston slidable' in a cylinder, or a flexible diaphragm or bellows, and as already stated may b used in different manners, for instance to actuate the admission valve of a prime mover, the carburetor throttle of an internal combustion engine, or "may be employed'to adjust the pitch of a variable-pitch propeller driven from an aircraft engine, in order to control the speed of said prime mover, internal combustion engine, or aircraft engine,

, respectively. The foregoing obviously applies to of the governors herein-disclosed.

The foregoing governors are of the centrifugal type, that is include engine-driven flyballs trans-' that may be substitutedgfor the governor of Fig.

l. A fuel transfer pump of the gear type 228 including an idler gear 222 and a driving gear 224 keyed in a shaft 228 supported in bearings 228 and 288 is driven from the engine by way of a pinion 282. A rod 284 tightly mounted in a lon Y gitudinal central bore of shaft 228 andaxially adjustable by means -of.a threaded portion 288 and a lock nut 288 issec'ured to the lower end of a'tension coil spring 248. The upper end of said spring is attached to. a supply valve 242 slidably and rotatably mounted in a bore coaxial pressure side of a spring-loaded valve 288, and by means of an orifice 288 adjustable by a needle valve 282 with groove 248. 'The discharge port 218 of the transfer pump 228 communicates by way of port 214 with the spring compartment 212 and, through an orifice 218 adjustable by the fuel-feed line 48 and thefuel injection pumps I8 of Fig. l. v V

, The transfer pump 228, drawing fuel from the supply line 284 in which the pressure is kept substantially constant, discharges a volume'of fuel proportional to the engine speed through the orifice 21.8 thusdetermining on opposite sides of said "orifice a difference of pressure that is proportional to the squareof the engine speed. As-

suming the orifice 288 to be closed ,by the needle valve 282, owingto the difference of fuel pressure'between chambers 212 and 282 a hydraulic load is applied to the valve that tends to lift the latter and has the same character as the centrifugal load transmitted to the valve 88 of Fig. 1 by the flyba-lls. .Said hydraulic load is balanced by the load exerted on valve 242 by the tension spring 248. The compensating device being inoperative and no restraining action being exerted on the pilot valve 242, the governor is unstable. If both orifices 288 and 288 are open the pressure in compensating chamber 282 has a value comprised between the pressures in line 288 and in supply line 284. Assuming again. for'simplicity's sake, the fuel pressure in fuel supply line 284 to have the surrounding atmospheric value, for a given adjustment of needle valves 288 and 282- the ratio between the pressures in line 288 and in compensating chamber 282 has a definite value.

- Said compensatingand restraining eifect, tending to lift the governor valve 242 against the load of spring 248, is thus equivaient'to that described in connection with Fig.- 1. Furthermore, axial upward or downward displacements of valve 242 again cause a decrease or increase ofpressure in line 288 and a decrease orincrease of engine fuel supply respectively. The maximum fuel pressure is determined by valve 288. It is therefore evidentthat the operation of the governors of Figs. .1 and 6 is similar. However in the governor 244the speed control lever 288, instead of adjusting the load of the governor, spring, controls by way of the needle valve 218 the open area of orifice 218. Changes in the adjustment of lever 280 cause a modification of the pressure difference between chamber 212.and compensating chamber 252 and therefore a variation of engine speed. The valve 242 is carried along in rotation from shaft 226 through rod 234 and spring 240, so as to reduce the effect of friction resistance tending to oppose the axial displacement of the only movable part of the governor.

While in the previously described governors, for a given adjustment thereof,the speed droop is smaller and the energy is larger at high speed than at low speed, in the governor of Fig. 6, in which the load of spring 240 is substantially independent of the engine speed, the energy and I the speed droop are also substantially independload proportional to the square of the engine speed. At the upper end of the valve 8. compensating chamber is provided. The total amount of fuel discharged by the transfer pump, minus the negligible amount flowing through the compensating chamber, is led through line 310 to the fuel feed line i2? of Fig. 3, while line M2 is connected with the return line I30 of the same Fig. 3. The fuel injection pumps I24 are connected in parallel between lines I22 and I30. The fuel lines are of sufilciently large section so as not to create objectionable differences of pressure in the various points of the pressure system. The operation of this form of governor is otherwise similar to that of governor 244.

In the governor 322 of Fig. 8, which is interchangeable with governor 488 of Fig. 4, lubricating. oil at substantially atmospheric pressure or other constant pressure is drawn through line 326 and duct 32 6 by a transfer pump, not shown, and discharged in volume proportional to the engine speed through an orifice-336 adjustable by way of a needle valve 338, thus creating a difference of pressure, proportional to the square of the engine speed, at the opposite ends of the pilot valve 346. The oil pressure beyond the orifice 336, at the upper end of valve 346 and in the upper groove 340 of the same is kept at a substantially constant pressure by means of a spring loaded valve 344, while in the lower groove of valve 346 the oil pressure is the same as in supply line 324. When the valve 346 is in its neutral position, as shown in Fig. 8, its intermediate portion defined by said grooves covers port 348 connected by way of line 354 with line H98 of Fig. 4. The oil pressure in line 364 thus controls the engine fuel supply. An upward displacement of valve 346, or a downward displacement of the same, establishing a communication between line 394 and lower groove 323 or upper groove 340 of valve 346, causes a decrease or an increase respectively of the pressure in line 354. At the lower end of valve 346 the spring compartment or compensating chamber is connected through an orifice adjustable by means of needle valve 334 with-the discharge port 330 of the oil pump, and through the orifice 350 adjustable by way of needle valve 352 with line 354. Anincrease or decrease of pressure in line 354 thus produces an-increase or decrease respectively of the pressure in the compensating chamber, resulting in a compensating load applied upwardly to the valve 346 against the action of the governor spring, which loadis larger or smaller when the engine load is higher or lower. The operation of governor 322 is therefore similar to that of the previously described governors.

' Fig. 9 shows a partial modification of the governors of Figs. 6 to 8 whereby the engine speed may be set by adjusting the load of spring 364 the lower end of which is secured to a splined rod 366 slidable in a splined hole axially broached in the governor shaft. A thrust bearing 310 has its inner race secured to rod 366 while its outer race is carried by a bracket 312 attached to a rod 314 slidable in an axial :bore of the idler gear shaft 316. A pin 318 carried by rod 314 engages a fork machined at the lower end of lever 380. The load of spring 364, and in turn the engine speed, may thus be set by way of said lever.

In the foregoing injectionsystems the adjustment of the injection pumps corresponding to the actual maximum delivery per stroke is determined either by the screw 46 limiting the displacement of rack 35 or by the adjustment of the maximum pressure regulating valve. The actual maximum fuel delivery per stroke of the injection pumps is substantially independent of the engine speed, being only affected by changes of volumetric efliciency versus engine speed. However in many applications it is desirable that the engine torqueshould be considerably larger at low speed than at high engine speed. To that end the maximum pressure regulating valve 64 of Fig. 1 may be modified as shown in Fig. 10 in which the discharge port 396 of the fuel transfer pump 392 is connected by way of duct 398 with the upper chamber of a spring-loaded maximum pressure regulating valve 400, and through an orifice adjustabie by means of a needle valve 402 with a line 408 leading fuel to the feed line 40 of Fig. l, with a line 4|0 connected with the governor, and with a by-pass 404 communicating with the inlet port of the transfer pump 392. Said by-pass 40a is controlled by valve 400 in such a way that when the fuel pressure in conduit 393 reaches a predetermined value the annular groove 606 of valve 400 registering with by-pass 404 establishes a communication between discharge and inlet ports of pump 392 thereby preventing a further increase of pressure in conduit 396. Thetotal fuel delivery of pump 392 is forced through the orifice adjustable by'needle valve 402 thereby creating a difference of pressure proportional to the square of the engine speed between conduit 396 and line 408. The maximum value that the fuel pressure may attain in line 406, and in turn the maximum value of the discharge per cycle of the injection pumps, is therefore smaller at high engine speed than at low speed. Decreasing or increasing by means of needle valve 402 the area of the orifice causes the difference between the maximum fuel discharge per stroke at low and high engine speed to increase or decrease respectively. By variously adjusting the needlr valve-402, the load of the spring of valve 400 and the screw 46 different characters of engine torque versus engine speed may be obtained.

The torque controlling device of Fig. 10 may obviously be introduced in the various forms of governors described'above, for example to the governor 322 of Fig. 8, as shown in Fig. '11 in which lubricating oil is drawn from the supply line II. and discharged by a pump into the orifice 420 connected by duct 424 with the inner end of the maximum pressure regulating valve 42-8. The pressure drop beyond the orifice adjusted by 'needle valve 422 increases with the engine speed and varies with the adjustment of said-needle valve. The oil pressure in the upper groove of the pilot valve, and in turn the maximum value of the pressure in line 430 leading oil to the injection pumps and the maximum value of fuel delivery per stroke are therefore smaller at high engine speed than at low engine speed.

Fig. 12 shows the application of the torque controlling device to the governor 300 of Fig. 7. Fuel is drawn from the supply line by a transfer pump and discharged into duct 2 connected with the chamber at the inner end of valve 8. The latter prevents the pressure in duct 2 from rising above a predetermined value. The fuel discharged into duct 2 flows past an orifice adjusted by needle valve 4 thus determining a pressure drop that increases with the engine speed. The maximum value of the fuel pressure in lines 450 and 452, between which the injection pumps are connected in parallel, and in turn the maximum value of the fuel discharge per stroke of the latter are therefore smaller at higher engine speed than at lower engine speed, and the portional to the square of.the speed of said prime mover, a pressure chamber at one end of said valve for applying a pressure load thereto, and fluid flow communication means between said chamber and said fluid containing means for varying said pressure load applied to said valve difference therebetween may be varied by modifying the adjustment of needle valve 4.

These embodiments of the invention have been shown merely for purpose of illustration and not as a limitation of the scope of the invention; and while in these embodiments the pilot valve is actuated in response to changes of speed of a prime mover, it will be appreciated that the m vention may also be used in connection with regulators actuated in response to one or more operative conditions other than speed, and with automatically controlled servomotors in which it is desired to avoid the danger of hunting. It is therefore to be expressly understood that the invention is not limited to the specific embodiments shown. but may be used in various other ways, and various modifications may be made to suit different requirements, and that'other changes,

substitutions, additions and omissions may be made in the construction, arrangement and manner of operation of the parts within the limits or scope of the invention as defined in the following claims.

Where claims are directed to less than all of the elements of the complete system disclosed,

they are intended to cover possible uses of the recited elements in installation which may lack the non-recited elements.

Certain features disclosed herein are claimed in I my 'copending patent application Serial- No. 533,417, flied April 29, 1944.

What I claim is:

1. In a control system for prime mover having fluid containing means'and pressure actuated control means operatively connected with first resilient means and adapted to be linked to said prime mover for increasing or decreasing the supply of actuating substance thereto in response to an increase or decrease respectively of the fluid pressure in said containing means, a slidable piston valve for controllingthe pressure of said fluid therein, second resilient means for applying a load to said valve tending to move the latter in a direction to increase the pressure of said fluid, means for applying to said valve a load directed against said resilient load and substantially Proa fluid pressure actuated resiliently loaded control.

means for increasing or decreasing the engine fuel supply upon an increase or decrease respectlvely of pressure in said containing means. a slidable piston valve for controlling the pressure of said fluid therein, means for applying to said valve an adjustable resilient load tending to move the latter in a direction to increase the pressure of said fluid, engine driven flyweights for applying to said valve a centrifugal force directed against said resilient load, a chamber atone end of and deflned in part by said valve, reservoir means vented to the atmospheric pressure, fluid duct means'including flow restricting orifices between said fluid containing means, said chamber and said reservoir means for keeping the effective pressure in said chamber substantially proportional to the effective pressure in said containing means, the ratio of proportionality therebetween being dependent on the relative effective areas of said orifices, the pressure in said chamber exerting on said valve 9. fluid pressure load directed against said resilient load whereby the adjustment of said valve is dependent on-said centrifugal force acting against said resilient load minus said fluid pressure load, and upon an increase or decrease of engine fuel supply the equilibrium of said valve is resumed for a decreased or increased value respectively of' engine'speed, and means for adjusting the effective area of one at least of said oriflces to control said ratio of proportionality and thereby the diflerence of engine speed between no load and full engine load.

3. In a fuel control system for internal combust'ion engine including fluid containing means and for establishing a fluid flow communication between said pump an said control means, oriflce means for restricting said flow to create a pressure differential substantially proportional to the square of the engine ,speed, an axially slidable plunger valve for controlling the pressure iri said containing means, means for applying a resilient load to said valve tending to move the latterin a direction to IncreaseJthe pressure in said containing means, pressure chambers at the ends of said valve in fluid'flqw communication with the upstream and downstream sides of'said orifice means for applying to said valve a differential pressure load directed against said resilient load, duct means having therein fluid at substantially constant pressure, and fluid flow communication means including flow restricting means between one of said chambers and said duct means whereby an increase or decrease of pressure in said containing means causes a corresponding variation of pressure in said last mentioned chamber which increases or decreases respectively said differential pressure load applied to said valve, thereby causing the engine speed to be higher at no load than at full engine load.

' 4. In a fuel control system for internal combustion engine including pressure actuated control means for varying the engine fuel supply asa predetermined function of the pressure of a liquid actuating said control means, and engine driven means for delivering a flow of said liquid substantially proportional to the engine speed, conduit means for providing a hydraulic connection between said engine driven means and said control means, orifice means for restricting said between said pump means and said control means,

- chamber communicating with one side of said flow to produce a pressure drop substantiallyproportional to the square of the engine speed, a slidable plunger valve for controlling the pressure of said liquid actuating said control means, means for applying a resilient load to said valve tending to move the latter in a direction to increase the engine fuel supply, duct means containing liquid at substantially constant pressure, pressure chambers at the endslof said valve communicating with opposite sides of said orifice means for applying a difierential pressure load to said valve dependent on the engine speed and directed against said resilent load, one of said chambers also communicating with said duct means whereby said differential pressure load is also dependent on the pressure of said liquid actuating said control means and causes the engine speed to be higher for no engine load than for full engine load, and means for adjusting said orifice means to control the engine speed.

' 5. In a fuel control system for an internal combustion engine including pressure actuated control means for varying the engine fuel supply in response to changes of pressure of a liquid actuating said control means and engine driven pump means for delivering a flow of said liquid substantially proportional to the engine speed, conduit means for providing a hydraulic connection between said pump means and said control,

means, orifice means for restricting said flow to produce a pressure drop substantially proportional to the square of the engine speed, a valve for controlling the pressure of said liquid actuating said control means, means for applying a resilient load to said valve tending to move the latter in a direction toincrease the engine fuel supply, duct means containing liquid at substantially constant pressure, pressure chambers in :communication with opposite sides of said orifice means for applying to said valve a differential pressure load dependent on the engine speed and directed against said resilient load, one of said chambers also communicating with said duct means whereby the pressure in said last mentioned chamber and in turn said diiferential pressure load is also dependent on the pressure of said liquid actuating said control means and thereby causes the engine speed to be higher for no'engine load than for full engine load, and means for adjusting said resilient load to control the engine speed.

6. In a fuel control system for internal comorifice means, and said second chamber having connections including flow restricting means with I said duct and with the opposite side of said orifice means, for applying to said valve a differential pressure load directed against said resilient load and dependent on the engine speed and on the pressure of said liquid actuating said control means to cause the engine speed to be higher for no load than for full engine load, one at least of said flow restricting means being adjustable to 'gine speed and fuel supply. 7 8. In a control system for internal combustion vary the difference of engine speed between no load and full engine load.

7. In a fuel control system for internal combustion engine having hydraulically operated control means for increasing or decreasing the engine fuel supply in response to an increase or decrease respectively of the pressure of a liquid column connected with said control means, a pressure regulating unit therefor including an engine driven pump having a rotating shaft, orifice means for restricting the discharge flow of said pump, a slidable plunger'valve coaxial with said shaft for controlling the pressure of said liquid column and in turn the engine fuel supply, resilient means connected with said shaft and with said valve for rotating the latter and applying thereto a resilient load tending to move said valve in a direction to increase the engine fuel supply, duct means containing liquid at substantially constant pressure, pressure chambers at the ends of said valve, and connections-including at least two flow restricting orifices betweensaid chambers, the upstream and downstream sides of said first mentioned orifice means and said duct means for applying to said valve a differential pressure load directed against said resilient load and increasing or decreasing with an increase or decrease respectively of the en engine having fluid pressure actuated control means for increasing or decreasing the engine fuel supply upon an increase or decrease respectively of the pressure of a fluid actuating said control means, an engine driven pump, and conduit means for connecting said pum with said A control means, orifice means in said conduit means between said pump and said control means for producing a fluid pressure drop increasing with the engine speed, resiliently loaded valve means for keeping the pressure upstream of saidorifice means substantially constant whereby the pressure downstream of the latter actuating said control means decreases with an increase of engine speed thereby causing the enbustion engine including hydraulicallyactuated control means for varying the engine fuel supply in response to changes of pressure of a liquid actuating said 'control means, and engine driven pump means for delivering a flow of said liquid substantially proportional to the engine speed, conduit means for providing a communication said control means, an engine driven pump, and conduit means for'connecting said pump with said control means, orifice means in said conduit means between said pump and said-control means for restricting the flow of fluid supplied by said pump to produce a drop of pressure increasing with the engine speed, pressure regulating means for limiting the pressure upstream of said orifice means to a substantially constant value whereby the maximum value of the pressure that said fluid downstream of said orifice means actuating said control means may attain decreases with an increase of engine speed thereby causing the maximum engine fuel supply and the maximum enginetorque to be higher at low speed than at high engine speed, and valve means connected with resilient means and actuated in response to the engine speed for regulating the pressure of said liquid actuating said control means to govern the engine speed.

10. In a control system for internal combustion engine having fluid pressure actuated control means for increasing or decreasing the engine fuel supply in response to an increase or decrease respectively of-the pressure of a fluid actuating said control means, an engine driven pump, and conduit means for.connecting said pump with said control means, orifice means in said conduit means between said pump and said control means for restricting the flow of fluid supplied by said pump to produce a drop of pressure increasing with the engine speed, resiliently loaded pressure regulating valve means actuated in response to the pressure upstream of said orifice means for decreasing the maximum value of the pressure which said fluid downstream of said orifice means actuating said control means may attain with an increase of engine speed thereby causing the maximum engine fuel supply and the maximum engine torque to be higher at low speed than at high engine speed.

11. In a contrbl system for internal combustion engine having control means for increasing or decreasing the engine fuel supply in response to an increase or decrease respectively of the pressure of a fluid actuating said control means, an engine driven pump, and conduit means for connecting said pump with said control means, positive'stop means cooperating with said control means for determining the absolute maximum engine fuel supply, orifice means in said conduit means for restricting the flow of fluid delivered,

by said pump to produce a drop of pressure which increases with the engine speed, resiliently loaded pressureregulating valve means actuated in resp nse to thepressure upstream of said orifice means for decreasing the maximum value of the pressure downstream of said orifice means actuating said control means with an increase of engine speed whereby the engine torque is higher at low than at high engine speed and the difference therebetween is dependent on the size of said orifice means, and resiliently loaded means adjustable in dependence of the engine speed and pressure of said liquid actuatin said control means for varying the latter pressure to govern the engine speed.

12. A governor including 9, hydraulic servomotor, a plunger valve controlling said servomotor, a fluid pump having a rotatable but not axially slidable shaft coaxial with said valve, a flow restricting orifice on the discharge side of said pump to determine a fluid pressure drop substantially proportional to the square of the pump speed, fluid pressure chambers at the ends of said valve, one

of said chambers being connected with the up- 1 stream side of said orifice and the other with the downstream side thereof, and a spring connected by means of thrust and torque transmitting attachments with said shaft and valve to rotate the latter and resiliently oppose axial motion thereof. 13. A governor as set forth in claim 12 further including (it adult means having, therein flow restricting means between said servomotor and one of said chambers whereby the fluid pressure in said chamber varies with changes of adjustmen of said servomotor.

14. A regulating device including a servomotor a slidable member for controlling said servomo tor, means for axially moving said member, con tinuously turning means coaxial with said mem ber, a coil spring having its ends attached by means of thrust and torque transmitting connections to said turning means and to said member,

and means for preventing axial motion of the spring end connected with said turning means, whereby said spring maintains said member in continuous rotation and exerts an axial load thereon dependent upon the axial adjustment of said member.

15. A governor having a hydraulic servomotor,

'a plunger valve controlling said servomotor, a

rotatable shaft coaxial with said valve and carrying flyweights for shifting said valve, a member coaxial with said shaft and connected therewith so as to be slidable but not rotatable relatively to said shaft, a coil spring for opposing outward motion of said flyweights, said spring having its ends connected by means of thrust and torque transmitting attachments with said shaft and with said valve respectively, whereby said spring causes totation of said valve, and control means for altering the axial adjustment of said member to vary the axial resilient load exerted by the spring on said valve.

18. A hydraulic governor having a slidable pilot valve, flyweights for shifting said valve, a continuously rotating member coaxial with said valve, means for controlling the axial adjustment of said member independently of the axial motion of said valve, and a coil spring coaxial with said valve for opposing outward motion of said flyweights, said spring having its ends connected by means of thrust and torque transmitting attachments with said member and valve, respectively.

17. A hydraulic regulating device including a pilot valve element, a continuously rotating member coaxial with said element, a coil spring having its ends connected by means of thrust and torque transmitting attachments with said member and element respectively for causing said element to rotate continuously and exerting thereon an axial load which varies with changes of axial adjustment of said element, and variable pressure fluid containing means defined in part by said element for exerting an operative variable axial pressure load on said element.

18. A fluid pressure actuated regulating device including. a fiuid pump having a rotatable shaft, 9. slidable valve coaxial with said shaft, variable pressure fluid containing means defined in part by said valve for exerting an operative axial load thereon, and spring means connected by way oi thrust and torque transmitting attachments with said shaft and with said valve for causing rotation of said valve and resiliently opposing axial motion thereof.

19. A regulating device including a fluid pressure actuated servomotor, a slide valve controlling said servomotor, a fluid flow restricting orifice, two

asseaao I fluid chambers at the opposite ends of said valve connected with the upstream and downstream sides of said orifice respectively, a fluid flow connection between said servomotor and one of said chambers to cause pressure variations in the latter with changes of adjustment of said servomov tor, a continuously rotating member coaxial with said valve but not slidable therewith, and a spring connected by means or thrust and torque trans-. mitting attachments with said member and valve to rotate the latter and resiliently oppose the axial 6 motion thereof.

FERDINANDO CARLO REGGIO. 

